1 It is an application of the Prophetic command
Narrated Anas bin Malik ( may Allah be pleased with him ):
The Messenger of Allah ( may the peace and blessings of Allah be upon him ) said: “Marry women who are loving and very prolific, for I shall outnumber the peoples by you."
Abu Dawud and Nasa’i transmitted it.
2 Working is an application of the prophetic command
Abu Hurairah (May Allah be pleased with him) reported:
The Messenger of Allah ( may the peace and blessings of Allah be upon him ) said, "It is better for anyone of you to carry a bundle of wood on his back and sell it than to beg of someone whether he gives him or refuses."
[Al-Bukhari and Muslim].