Sayyiduna Jabir bin Abdullah (may Allah be pleased with them both) narrates from the Messenger of Allah (peace and blessings be upon him): "There are three people who, if they do something out of trust in Allah and seeking reward, it is a duty upon Allah to help them, and Allah will also bless their affairs.
1. The one who strives to free his neck (from slavery): out of trust in Allah and seeking reward, it is a duty upon Allah to help him, and his affair will be blessed.
2. The one who marries out of reliance on Allah and seeking reward: it is a duty upon Allah to help him, and his affair will be blessed.
3. The one who revives barren land out of reliance on Allah and seeking reward: it is also a duty upon Allah to help him, and his affair will be blessed."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب المكاتب / 21613