[3] Allah raised the Prophet's name in numerous ways, such as his name is mentioned twice in the call to prayer five times a day, as well the second call to prayer; at the end of each of the five daily prayers; believers invoke Allah’s blessings upon him and his family; and upon reverting to Islam, his name is mentioned, etc.
[4] In Arabic grammar, if a definite noun is repeated, it is referring to the same thing. However, if an indefinite noun is repeated, it is referring to two different things. So here in this and the coming verse they refer to one hardship (a definite noun) and two eases (an indefinite noun), which manifests Allah's favors upon His servants even in times of hardships.