Does the act I performed (returning the lost money despite my need for it) permit me to ask Allah to grant me a job by virtue of this good deed? Is there any text from the Sunnah or a story that approximates this?

The questioner is congratulated for his trustworthiness and his diligence in prayer and fasting. It is prescribed for a Muslim to ask Allah Almighty through his good deeds, as did the Companions of the Cave who asked Allah through their deeds, among whom was one who paid his laborer his wages after investing them.