211 – Abū Qatādah (may Allah be pleased with him) reported that the Messenger of Allah ﷺ said: “When any one of you enters the mosque, he must not sit down until he has prayed two rak‘ahs.” Agreed upon (1).

Vocabulary of the ḥadīth
– “When he enters”: idhā is a conditional particle and its verb is dakhala (to enter).
– “let him not sit”: lā is prohibitive; the verb that follows is in the jussive mood and serves as the consequence of the condition.
– “two rak‘ahs”: a part has been mentioned while the whole is intended—a frequent usage, and the part is singled out because of its special importance.

Points derived from the ḥadīth

1. A person who enters the mosque is forbidden to sit until he has performed two rak‘ahs, known as the Greeting of the Mosque.
2. The literal wording suggests that these two rak‘ahs are obligatory, yet the majority of scholars interpret them as recommended, citing the Prophet’s ﷺ statement to the man who stepped over people’s shoulders: “Sit down, for you have caused annoyance,” and he did not command him to pray; likewise, when he ﷺ taught another man the pillars of Islam, he mentioned only the five daily prayers, not the Greeting of the Mosque.
3. The apparent sense is that the two rak‘ahs may be offered at any time, even during periods when voluntary prayer is normally discouraged. There is, however, a scholarly dispute on this point that will be discussed, Allah willing.
4. The surface meaning indicates that once the entrant has sat down the greeting is lost; nevertheless, a number of scholars hold that if only a brief interval has passed, he may still make it up and perform the two rak‘ahs, based on what Ibn Ḥibbān narrated.