As to thy question concerning interest and profit on gold and silver: Some years ago the following passage was revealed from the heaven of the All-Merciful in honour of the one who beareth the name of God, entitled Zaynu’l-Muqarrabin —upon him be the glory of the Most Glorious. He—exalted be His Word—saith: Many people stand in need of this. Because if there were no prospect for gaining interest, the affairs of men would suffer collapse or dislocation. One can seldom find a person who would manifest such consideration towards his fellow-man, his countryman or towards his own brother and would show such tender solicitude for him as to be well-disposed to grant him a loan on benevolent terms.  Therefore as a token of favour towards men We have prescribed that interest on money should be treated like other business transactions that are current amongst men. Thus, now that this lucid commandment hath descended from the heaven of the Will of God, it is lawful and proper to charge interest on money, that the people of the world may, in a spirit of amity and fellowship and with joy and gladness, devotedly engage themselves in magnifying the Name of Him Who is the Well-Beloved of all mankind. Verily He ordaineth according to His Own choosing. He hath now made interest on money lawful, even as He had made it unlawful in the past. Within His grasp He holdeth the kingdom of authority. He doeth and ordaineth. He is in truth the Ordainer, the All-Knowing.
[1 One of the early believers who is best known to the friends for his reliable transcriptions of the Tablets of Bahá’u’lláh.
(See Memorials of the Faithful pp. 150-153.)]
[2 Such loans as bear no interest and are repayable whenever the borrower pleases.] (Bahá’u’lláh, Tablets of Bahá’u’lláh, p. 132-133)
Economy was a very rigid principle with Shoghi Effendi and he had very stern ideas on money matters. He more than once refused to permit an individual to make the pilgrimage who he knew was in debt, saying he must first pay his debts.
(Ruhiyyih Khanum, The Guardian of the Bahá’í Faith, p. 57)
Even though Shoghi Effendi would urge every believer to sacrifice as much as possible for the sake of contributing towards the fund of the National Assembly, yet he would discourage the friends to incur debts for that purpose. We are asked to give what we have, not what we do not possess, especially if such an act causes suffering to others.
(Shoghi Effendi, Lights of Guidance, p. 250)
I hope thou wilt become as a rising light and obtain spiritual health—and spiritual health is conducive to physical health—so that thou mayest be enabled to liquidate thy debts and be strengthened to attain the blessing of the Forgiving Lord.
(‘Abdu’l-Bahá, Tablets of ‘Abdu’l-Bahá v2, p. 305-306)
If a Bahá’í owes a debt to a person who breaks the Covenant he must be sure that it is repaid and that his obligations are met.
(Universal House of Justice, Lights of Guidance, p. 186)
In connection with the demands for payment of which thou hast written in thy letter, it is manifestly clear that anyone who hath the ability to settle his debts, and yet neglecteth to do so, hath not acted in accordance with the good pleasure of the one true God. Those who incur debts should strive to settle them with all diligence and application. God’s binding commandments with respect to trustworthiness, uprightness and the honouring of rights have been recorded in clear and perspicuous language in all the sacred Books, Tablets, Scriptures and holy Writings. Well is it with him whom the fleeting vanities of the world have not deprived of a lasting adornment, and whom avarice and negligence have not shut out from the illumination of the sun of trustworthiness. These matters, however, depend on the existence of ability, for the making of a demand is contingent upon ability to meet it. By the Lord of the Book, the former is not permissible in the absence of the latter. To this testifieth the Verse: “Respite thy debtor till he findeth means to pay.”
(Bahá’u’lláh, The Compilation of Compilations vol II, p. 336)
In determining the amount a believer should pay, he should first deduct any debts and expenses he may have, and pay nineteen per cent of the remainder of his capital if it is equal to at least nineteen mithqals of gold. If you decide that you wish to observe this Law of the Aqdas at the present time, you should determine the total value of your inheritance in cash and other assets less any expenses or debts you may have, and consider the circumstances under which you may be able to pay Huququ’lláh on the net value of your inheritance.
(Universal House of Justice, The Compilation of Compilations vol. I, p. 522)
Many ecclesiastics in Persia have, through innumerable designs and devices, been feeding on illicit gains obtained by usury. They have contrived ways to give its outward form a fair semblance of lawfulness. They make a plaything of the laws and ordinances of God, but they understand not. However, this is a matter that should be practised with moderation and fairness. Our Pen of Glory hath, as a token of wisdom and for the convenience of the people, desisted from laying down its limit. Nevertheless We exhort the loved ones of God to observe justice and fairness, and to do that which would prompt the friends of God to evince tender mercy and compassion towards each other. He is in truth the Counsellor, the Compassionate, the All-Bountiful. God grant that all men may be graciously aided to observe that which the Tongue of the One true God hath uttered. And if they put into practice what We have set forth, God—exalted be His glory—will assuredly double their portion through the heaven of His bounty. Verily He is the Generous, the Forgiving, the Compassionate.
(Bahá’u’lláh, Tablets of Bahá’u’lláh, p. 132)
Many of the Bahá’ís of ‘Akká needed financial support to be able to abandon, even for a short while, their homes and their means of living. ‘Abdu’l-Bahá Himself borrowed a large sum of money from an American in Paris, to facilitate their move to Egypt.
(H.M. Balyuzi, ‘Abdu’l-Bahá - The Centre of the Covenant, p. 112)
Our debts, however, should be considered as sacred and take precedence over any other thing [i.e., payment of debts comes before contributions to the Cause] for upon this principle does the foundation of our economic life rest.
(Shoghi Effendi, Principles of Bahá’í Administration, p. 20)
Outstanding debts and payments of Huquq should be settled from the remainder of the estate, but if this is insufficient for the purpose, the shortfall should be met from his residence and personal clothing.
(Bahá’u’lláh, The Kitáb-i-Aqdas, p. 130)
QUESTION: Which is to take precedence: the Huququ’lláh, the debts of the deceased or the cost of the funeral and burial? ANSWER: The funeral and burial take precedence, then settlement of debts, then payment of Huququ’lláh. Should the property of the deceased prove insufficient to cover his debts, the remainder of his estate should be distributed among these debts in proportion to their size.
(Bahá’u’lláh, The Kitáb-i-Aqdas, p. 109)
That inter-governmental debts have imposed a severe strain on the masses of the people in Europe, have upset the equilibrium of national budgets, have crippled national industries, and led to an increase in the number of the unemployed, is no less apparent to an unprejudiced observer.
(Shoghi Effendi, The World Order of Bahá’u’lláh, p. 35)
The Guardian suggests that you contact Mr. ..., and press him to discharge his debt to the believer in Fiji whom he has so grievously wronged, pointing out to him that surely, if he expects any forgiveness from God, the first pre-requisite is to conduct himself honestly.
(Shoghi Effendi, Letters from the Guardian to Australia and New Zealand, p. 103)
The inheritance should not be divided until after the payment of the Huququ’lláh (The Right of God), of any debts contracted by the deceased and of any expenses incurred for a befitting funeral and burial.
(Bahá’u’lláh, Synopsis and Codification of the Kitáb-i-Aqdas, p. 45)
The settlement of debts is a most important command set forth in the Book. Well is it with him who ascendeth unto God, without any obligations to Huququ’lláh and to His servants.
(Bahá’u’lláh, Huququ’lláh, #22)
Therefore it beseemeth thee to meet thine obligation to the Right of God first, then to direct thy steps toward His blessed House. This hath been brought to thine attention as a sign of favour.
(Bahá’u’lláh, Compilation of Compilations vol. I, p. 499)
Thou hast asked which is to take precedence: the Huququ’lláh, the debts of the deceased, or the cost of burial. It is God’s command that the cost of burial take precedence, then payment of debts, then the Right of God. Verily He is the One Who will pay due recompense, the All-Rewarding, the All-Generous.
(Bahá’u’lláh, Lights of Guidance, p. 306)
Trust in God and engage in your work and practice economy; the confirmations of God shall descend and you will be enabled to pay off your debts. Be ye occupied always with the mention of Bahá’u’lláh and seek ye no other hope and desire save Him.
(‘Abdu’l-Bahá, Bahá’í World Faith, p. 375)
We have, according to the text of the Book, forbidden unto all men the practice of usury.
(Bahá’u’lláh, The Summons of the Lord of Hosts, p. 200)
With regard to interest on money, Bahá’u’lláh writes in the Tablet of Ishraqat as follows: — Most of the people are found to be in need of this matter; for if no interest be allowed, affairs (business) will be trammeled and obstructed. ... A person is rarely found who would lend money to anyone upon the principle of “Qar-i-hasan” (literally “good loan,” i.e. money advanced without interest and repaid at the pleasure of the borrower). Consequently, out of favor to the servants, We have appointed “profit on money” to be current, among other business transactions which are in force among people. That is ... it is allowable, lawful and pure to charge interest on money ... but this matter must be conducted with moderation and justice. The Pen of Glory has withheld itself from laying down its limits, as a Wisdom from His Presence and as a convenience for His servants. We exhort the friends of God to act with fairness and justice, and in such a way that the mercy of His beloved ones, and their compassion, may be manifested toward each other. ... The execution of these matters has been placed in charge of the men of the House of Justice, in order that they may act in accordance with the exigencies of the time and with wisdom.
(Bahá’u’lláh, Tablet of Ishraqat, Bahá’u’lláh and the New Era, p. 144)
Your Assembly should not deprive him of his voting rights … because he cannot, or will not, liquidate his debts.
(Shoghi Effendi, NSA USA - Developing Distinctive Bahá’í Communities)