A worshipper of Allah Ta'ala is closest to Allah Ta'ala when he/she is in worship. When a person is offering Salaat, he/she is like talking intimately with Allah Ta'ala. The Holy Prophet (Sallallahu alaihi wa sallam) says:
Translation of Hadith: A worshipper is close to Allah Ta'ala when he (or she) is in Sajdah. (Sahih Muslim, Hadith No. 875)
However, Allah Ta'ala did not send for the Holy Prophet (Sallallahu alaihi wa sallam) when He was in a particular form of worship, but sent Jibreel (May peace be upon him) when He (Sallallahu alaihi wa sallam) was sleeping. The whole journey of Meraj was in a state of wakefulness, but Jibreel (May peace be upon him) brought the summons for Meraj when the Holy Prophet (Sallallahu alaihi wa sallam) was resting. This shows that Allah Ta'ala loves even the resting of His Beloved Prophet (Sallallahu alaihi wa sallam) so much that the Lord Almighty rains His blessings on Him.
When resting, the Holy Prophet (Sallallahu alaihi wa sallam) is so close to Allah Ta'ala that a summons for a great journey is received. Just imagine how much do the favors of Allah Ta'ala rain upon Him when He (Sallallahu alaihi wa sallam) is engaged in Tawaf of the Ka’aba, when He (Sallallahu alaihi wa sallam) is supplicating, when He (Sallallahu alaihi wa sallam) is in Salaat, when He (Sallallahu alaihi wa sallam) is busy in spreading Islam. Even the sleep of the Holy Prophet (Sallallahu alaihi wa sallam) is such that He (Sallallahu alaihi wa sallam) Himself says:
Translation of Hadith: My eyes sleep, my heart stays awake. (Sahih Muslim, Hadith No. 3304)
That is the reason the Holy Prophet (Sallallahu alaihi wa sallam) described even the manner in which the angel entered the house. The sleep of common folk is of heedlessness. For the Prophets, sleep and wakefulness are both alike.