Abu Dawud

413. Commentary:
➊ This hadith is, in a way, an explanation of the first hadith: that if someone is delayed due to a valid (shar‘i) excuse and manages to perform one rak‘ah before sunset, it is as if he has caught the prayer within its time. This is a special mercy from Allah, the Exalted, for His servants. However, if one delays without an excuse, this is a sign of hypocrisy.
➋ There is a difference of opinion regarding the meaning of “the sun being between the two horns of Satan.” Imam Nawawi rahimahullah says: “It is said that this is a reality, and at the time of sunrise and sunset, Satan comes in front of the sun, so it appears as if the sun is rising or setting from between his head. And the worshippers of the sun also prostrate before it at these times, so he thinks that prostration is being made to him. It is also said that the two horns refer metaphorically to the elevation of Satan and the dominance of satanic forces, and that the disbelievers prostrate to the sun at the times of sunrise and sunset . . . . . .” End quote «والله أعلم»
➌ Exceptional cases should not be made into a rule or general principle.

512. Commentary:

➊ The meaning of the sun being between the two horns of Satan may also be that it is near setting; at that time, the worshippers of the sun perform their worship, which is a satanic act, and thus it has been described in the above words. Some scholars have taken it literally, that at the times of sunrise, sunset, and when the sun is at its zenith (directly overhead), Satan comes and stands near the sun in such a way that the sun is between his two horns, so that the worshippers of the sun also worship him. Perhaps for this reason, Muslims have been prohibited from performing prayer at these times. And Allah knows best.

➋ "He pecks four times (with his beak)." Since the sun is almost setting, he (the hypocrite) performs the prayer hastily. It appears as if a crow is pecking. He does not recite the prescribed remembrances and supplications of the prayer properly, because he has no inclination (towards the prayer); thus, some is recited, some is left out. Since there are four units (rak‘ahs), it is said "four pecks." Although there are eight prostrations (sujood) in them, due to performing them quickly, it is as if both together are equal to one peck.

➌ The prayer of a believer is adorned with tranquility, humility and submissiveness, and the prescribed remembrances.

Hadith Commentary: Benefits and Issues: (1)
To delay the ‘Asr prayer without any excuse or necessity to such an extent that the sun is about to set, and then to hastily perform the four units (rak‘ahs) in this last, constricted time—so quickly that even the amount of remembrance (dhikr) of Allah is very little and merely nominal—is a hypocritical manner of action. A believer should perform every prayer, especially the ‘Asr prayer, at its proper time with utmost tranquility and moderation. To hastily perform bowing (ruku‘) and prostration (sujud) is nothing but moving up and down like the pecking of a rooster.

(2)
During the era of Anas radi Allahu anhu, some governors from Banu Umayyah used to perform the ‘Asr prayer very late, and Anas radi Allahu anhu considered this practice to be wrong and contrary to the Sunnah. Therefore, he would instruct those who came to him to perform the ‘Asr prayer first, and afterwards he would narrate this hadith to them. He himself would also perform the ‘Asr prayer early at home, as is mentioned in the following narration.