:salam:
A Muslim should not sin willfully, assuming he can ask for forgiveness later on because nobody knows when death can overtake him. It could be before he gets a chance to repent.
Ask for non-riba based loans from friends or well-wishers and it is not sufficient, then keep asking Allah :swt: to open a way for your brother by increasing the Du'a in Tahajjud and after Fardh prayers. If you firmly resolve not to engage in any sin, Allah :swt: will surely make a way out for you.
Also, increase
istighfar as much as possible. Because the messenger of Allah, :saws: said: "من لزم الاستغفار ، جعل الله له من كل ضيق مخرجاً ومن كل هم فرجاً، ورزقه من حيث لا يحتسب" "
If anyone constantly seeks pardon (from Allah), Allah will appoint for him a way out of every distress and a relief from every anxiety, and will provide sustenance for him from where he expects not." [
Abu Dawud]
And Allah :swt: says that Nuh :as: said to his people,
And said, 'Ask forgiveness of your Lord. Indeed, He is ever a Perpetual Forgiver.
He will send [rain from] the sky upon you in [continuing] showers
And give you increase in wealth and children and provide for you gardens and provide for you rivers. [
Surah Nooh: 10-12]