From Abdullah who said: The Messenger of Allah (SAW) said to us: Oh you young people, whoever has the means among you, let him get married, for indeed it is best for lowering the gaze and safeguarding the crotch; and whoever does not have the means, he is obliged to fast, for indeed this will quell him.
Sahih Muslim, The book of marital relations


Scholars have differed regarding the intended connotation of “the means” [al-ba’ah] here, in two opinions that converge into a single meaning. The most correct of the two is that the linguistic intent in meaning is that of sex, and so it can be paraphrased as “Whoever among you is able to have sex due to the possibility of his resources, this being the resources for marital relations, let him get married, and whoever is not able to have sex due to his lack of resources, he is obliged to fast in order to eliminate his sex drive and to remove the evil of his semen, just like quelling will remove it.” This is the view found in the message to the young men who were presumed to be desiring women and not able to disentangle themselves and prevail. The second view is that the intended meaning of “means” here is the resources for marital relations, designated as anything necessary for them. So then the paraphrase: “Whoever among you has the resources for marital relations, let him get married, and for whoever the means are not possible, let him fast to eliminate his sex drive.” Someone who entertains those who hold this opinion over the other due to the fact that they say regarding His (SAW) words “And whoever does not have the means, let him fast”; this person might say: Someone incapable of sex does not need to fast in order to eliminate his sex drive, and the interpretation of “means” must therefore be resources. But the first group of people would respond as we have discussed in the first view, which is that it is phrased as “Whoever is not able to have sex due to his lack of resources, he being in need of sex, is obliged to fast.” But Allah knows better.