Overall meaning
Abu Jahm presented the Prophet ﷺ with a khamisah that had stripes and markings. In keeping with his noble character, the Prophet ﷺ would accept gifts in order to honour the giver, so he accepted the cloak and prayed in it. Because the designs caught the eye, however, they distracted him from complete presence of heart in his prayer—though he, upon him be peace, is perfect and only perfect deeds issue from him.
He therefore instructed that the patterned khamisah be returned to its donor, Abu Jahm. And so that no misgiving should remain in Abu Jahm’s heart, he ordered that Abu Jahm’s plain cloak—the one without any markings—be brought instead. Such was the perfection of his guidance, ﷺ.

Points derived from the hadith

1. Devotional humility (khushuʿ) in the prayer is prescribed, as is taking every measure that fosters it and avoiding whatever distracts during the prayer.
2. A minor distraction of the heart does not invalidate the prayer.
3. It is disliked to embellish mosques with decoration, engravings, or writing, because this preoccupies worshippers who look at it.
4. It is permissible for men to wear garments that have patterns.
5. It is recommended to accept a gift in order to gladden the giver and show him affection.
6. There is no harm in returning a gift for a legitimate reason, provided the reason is explained to the giver so that no hard feelings arise.
7. The hadith highlights the Prophet’s ﷺ refined manners: he returned the patterned cloak yet asked for the plain one to show that he was not disdainful of the gift.

Shaykh al-Islam Ibn Taymiyyah said:
There is no doubt that the fewer the whisperings in a prayer, the more perfect it is; and two matters help one achieve this: a strong motivating cause and weak distractions.

As for the first, it is the servant’s striving to understand what he is saying and doing, to reflect on the recitation, remembrances, and supplications, and to keep in mind that he is conversing with Allah Most High as though he sees Him—for the one who prays is indeed in intimate discourse with his Lord. Excellence (ihsan) is to worship Allah as though you see Him; for if you do not see Him, He certainly sees you. Whenever the servant tastes the sweetness of prayer, his longing for it becomes more intense, and this is commensurate with the strength of faith. The factors that strengthen faith are many: the heart’s knowledge of Allah, its love for Him, awe of Him, sincerity in dedicating the religion to Him, fear of Him, and hope in Him