Could you please explain the meaning of lending to God a beautiful loan? Does it refer specifically to giving people interest-free loans?
There are a number of verses of the Qur’ân that mention loaning to Allah a beautiful loan. They are:
“Who will loan Allah a beautiful loan so He may multiply it for him many times?” [Sûrah al-Baqarah: 245]
“Indeed, Allah took the covenant from the Children of Israel and We appointed twelve leaders among them. And Allah said: ‘I am with you if you perform prayer and pay alms and believe in My Messengers; honor and assist them, and lend to Allah a beautiful loan, verily, I will remit your sins and admit you to Gardens under which rivers flow.” [Sûrah al-Mâ’idah: 12]
“Who will loan Allah a beautiful loan so He may multiply it for him many times?” [Sûrah al-Hadîd: 11]
"Verily, those men and women who give charity and lend Allah a beautiful loan, it shall be increased many times and theirs shall be an honorable good reward.” [Sûrah al-Hadîd: 18]
“So fear Allah as much as you can; listen and obey, and spend in charity; that is better for you. And whosoever is saved from his own greed, they are the successful ones. If you lend to Allah a beautiful loan, He will double it for you and forgive you.” [Sûrah al-Taghâbun: 16-17]
“And establish prayer and pay Zakâh. And loan to Allah a beautiful loan.” [Sûrah al-Muzammil: 20]
In all of these cases, the term "beautiful loan" refers to spending in Allah’s cause specifically or spending in charity generally. It is not referring specifically to giving other people interest-free loans.
Ibn Kathîr,in his commentary on the Qur’ân, explains the meaning of a “beautiful loan” when he discusses Sûrah al-Taghâbun, verse 17. He writes: “Whatever you spend, then Allah will replace it, and on Him will be the reward of whatever you give away in charity. Allah considered giving charity as if it is a loan to Him.”
About Sûrah al-Hadîd, verse 11, Ibn Kathîr says: “Umar bin Al-Khattab said that this Ayah refers to spending in Allah's cause. It was also said that it pertains to spending on children. What is correct is that it is more general than that. So all those who spend in the cause of Allah with good intentions and a sincere heart fall under the generality of this verse.”
About Sûrah al-Hadîd, verse 18, Ibn Kathîr says: “Allah describes the reward that He will give to those who spend from their wealth, whether male or female, on the needy, the poor and the meek, meaning, they give in charity with a good heart seeking the pleasure of Allah. They do not seek worldly rewards or appreciation from those to whom they give in charity.”