the mosques would be filled with the voices of those making such announcements, distracting people from the remembrance of Allah and from the prayer. Thus, the evidence for this is both textual and rational.
His words, “other than mosques”: This includes everything that is a mosque. As for prayer halls, however, they do not fall under this ruling. Thus, if someone announces a lost item in a prayer hall in one of the offices or departments, there is no blame upon him, because such a prayer hall is not a mosque. This is why observing iʿtikāf (seclusion for worship) there is not valid; it has no mosque-greeting prayer; and it is not forbidden for a person in a state of major ritual impurity, nor for a menstruating woman, to remain there. It is like the place where a person prays in his home.
His words, “for a year”: that is, for a complete year. You should know that when the scholars use without qualification the terms ḥawl (year), ʿām (year), or sanah (year), they mean the lunar year—that is, the year determined by the lunar crescents. For the lunar year is the true year that Allah has appointed for His servants. Allah Most High says:
“Indeed, the number of months with Allah is twelve lunar months in the register of Allah from the day He created the heavens and the earth; of these, four are sacred.” [al-Tawbah 9:36]
These calendars that are based on non-lunar months are, in reality, arbitrary conventions not regulated by any fixed standard. Thus, you find that one month may have thirty-one days, while another may have, for example, twenty-eight days. Such months are not founded upon any principle. Lunar months, however, are founded upon a principle that Allah Most High established for people, as Allah Most High says:
“They ask you about the new moons. Say, ‘They are measures of time for people and for Hajj.’” [al-Baqarah 2:189]
And He says:
“And He determined it in phases, so that you might know the number of years and the reckoning.” [Yūnus 10:5]
Therefore, whenever you encounter the words ḥawl (year), sanah (year), or ʿām (year) in the statements of the people of knowledge, what is meant is the lunar year.