先知(SAW)的沉默,即他的认可,属于圣训(Sunnah),与他的言语和行为同等。因此,如果有人在先知面前,或在先知的时代做了某件事,而先知知晓此事,并且能够禁止,却保持沉默,对此未加斥责而予以认可,那么这便视为该行为是被允许的,做这件事的人也不受指责。这是因为,如果该行为不被允许,先知必定会禁止他,因为使者在知晓恶行(munkar)时不会保持沉默,所以他的沉默就是该行为被允许的证据。如果先知此前已经禁止过该行为,且禁令已为人所知,那么就不可能设想使者会保持沉默,因为那等于认可了被禁止的事情,而这对先知(ﷺ)来说是不可能的。至于他对处于穆斯林庇护之下的非信徒(ahl al-dhimmah)的沉默——他们经常去自己的教堂,而这是一种 kufr(不信)的行为——这并不表示他认可这种不信的行为,而是表示允许ahl al-dhimmah进行他们自己的崇拜,并且它不能作为去教堂被允许的证据。因此,要使沉默被视为圣训(即认可)所需具备的条件是:此前没有对该行为的禁令;使者(ﷺ)知晓此事,即该事是在他面前发生,或在他的时代发生且他知晓;并且使者能够禁止(阻止)它。除此之外,这种沉默便不被视为圣训。 所谓禁止的含义，是约束其行为者，而不是说使者不倾向于此。因为在先知面前有人吃了沙蜥，而他自己没有吃，当被问及时，他说：

The silence of the Prophet (SAW), i.e. His approval is from the Sunnah, it is like His saying and His action equally the same, so if one did an action in the presence of the Prophet, or in His era and He knew about it, and was able to forbid it, then He kept silent about it and approved it for him without dispraising his action; it will be looked, if there is no previous forbiddance for that action from the Prophet (SAW), and no forbiddance is known for it, then His silence about its doer, and His approval to him on it denotes the permissibility of that action and the lifting up of the blame for doing it. That is because, if his action is not permissible; the Prophet would forbid him, since the Messenger does not keep silence if He knows about an evil (munkar) action, therefore His silence is a daleel for the permissibility. If the Prophet had previously forbade that action and its forbiddance became known; the silence of the Messenger can not be imagined, because it would be an approval to do what is forbidden. And this is impossible for the Prophet (SAW). As for His silence about the kuffaar under the Muslims' protection (ahl al-dthimmah), who used to frequently go to their churches, which is a kufr action; it does not denote His approval to do the kufr, but it denotes leaving ahl al-dthimmah to perform their own worship, and it is not a daleel for the permissibility to go to the church. So the conditions to consider the silence to be from the Sunnah (approval) are: that there is no previous forbiddance for the action, and the Messenger (SAW) knew about it, i.e. it was done in His presence, or in His era and He knew it, and that the Messenger was able to forbid (prevent) it, except that the silence is not considered to be from the Sunnah. The meaning of the forbiddance it is restraining its doer, and not that the Messenger does not trend to it, because the dab lizard got eaten in the presence of the Prophet and He did not eat from it, and when He was asked He said:

"它不存在于我族的土地上，所以我发现自己厌恶它"，由布哈里辑录。因此，先知厌恶它并不等于禁止；他对吃它的人没有加以制止，这被视为对此事的默许，所以这是许可的证据。 另有传述，据纳非俄所述：伊本·欧麦尔听到牧羊人的笛声，便将两根手指放入耳中，并让骑着的骆驼偏离道路，同时说："纳非俄啊，你听到了吗？"我说："是的。"他便一直走远，直到我说"没有了"，他才放下手，让骆驼回到路上，并说："我曾看见安拉的使者ﷺ听到牧羊人的笛声时，也这样做过。"此段由艾哈迈德辑录。这并不构成对牧羊人的禁止，而是对此事的默许，也是笛声本身及聆听它为许可的证据。至于（先知ﷺ）掩耳，可能是他像避开许多许可之事那样而避开它，正如他避免在家中过夜留存一枚第纳尔或一枚迪尔汉，也避免食用蜥蜴。因此，使者ﷺ的沉默意味着不制止做此事的人，即便他表明了自己对此事的厌恶。

"It did not exist in the land of my people so I find myself detests it" compiled by Al-Bukhari. So being that the Messenger detests it is not of the forbiddance, and His none restraining those who ate it is considered to be silence about it, so it is a daleel for the permissibility. Also it was narrated from Naafi': That Ibn Omar heard the sound of a shepherd's pipe, then he put his finger tips in his ears, and deviated his riding camel from the way while he was saying: O Naafi' could you hear? I say: yes, then he keeps going away until I said no, then he put his hands down, and returned his riding camel to the way, and said: I saw the Messenger of Allah (SAW) when He heard the sound of a shepherd's pipe and He did like this" compiled by Ahmad. This is not considered to be forbiddance for the shepherd, but it is a silence about him, and it is a daleel for the permissibility of the pipe and the permissibility of hearing it, and as for blocking His hearing; it is possible that He avoided it as He used to avoid many permissible things, as He avoided to keep in His house dirham or dinaar overnight, and as He avoided eating the lizard. Accordingly, the silence of the Messenger means not restraining the one who does the action, even if He shows His self detest of the action.