Hawzah News Agency – Imam al-Sadiq peace be upon him says:

ضَمِنتُ لِمَنِ اقتَصَدَ أن لا يَفتَقِرَ.

I guarantee that he who adopts moderation would not become poor.

Source: al-Faqih, v. ۲2, p. 64, no. 1721