“The delegation of Allah are three: the one who goes forth in battle, the pilgrim, and the one performing ʿumrah.”

Narrated by al-Nasāʾī (no. 2625), Ibn Khuzaymah (no. 2511), and al-Bayhaqī in al-Kubrā (no. 10387), with the wording being theirs; and narrated by Ibn Ḥibbān (no. 3692), with the placement of “the one who goes forth in battle” delayed, from the ḥadīth of Abū Hurayrah (may Allah be pleased with him).
And with similar wording it was narrated by Ibn Mājah (no. 2892), from the ḥadīth of Abū Hurayrah (may Allah be pleased with him) as well.
Authenticated in Ṣaḥīḥ al-Jāmiʿ (no. 7112) and Ṣaḥīḥ al-Targhīb wa-l-Tarhīb (no. 1109).

Brief Explanation of the Hadith

This ḥadīth clarifies the virtue of certain great acts of worship whose performers are singled out with additional honor in the sight of Allah, the Exalted—namely, the one who goes forth in battle, the pilgrim, and the one performing ʿumrah. For the Prophet—may Allah’s peace and blessings be upon him—referred to them as the delegation of Allah, an honorific attribution that indicates the greatness of their rank, their nearness to their Lord, and their special status with Him.
They were called a “delegation” because they departed from their homelands, expended their wealth, and endured hardships in the cause of Allah, the Exalted. Thus, in meaning, they resemble delegations who go to kings and are met with honor and generosity. And Allah, the Exalted, is more deserving of generosity and munificence; therefore, He honors them with immense reward, abundant recompense, and expansive grace.
These three were grouped together due to their shared qualities of departing from their homelands, sacrificing life and wealth, and enduring hardship in the cause of Allah. By virtue of this, they are deserving of elevated rank and immense reward—each according to the sincerity and devotion that resided in his heart.
Others are also included with them with respect to the foundation of reward, such as one who travels in pursuit of knowledge or for maintaining ties of kinship, for he is rewarded for his journey and hardship according to his intention and sincerity. However, the special distinction of being honored with the title “the delegation of Allah” is exclusive to the one who goes forth in battle, the pilgrim, and the one performing ʿumrah—due to the explicit textual evidence to that effect and the greatness of the objectives of these acts of worship and the severity of their hardships.
In the ḥadīth there is a clarification of the virtue of striving in the cause of Allah, Hajj, and ʿumrah, and of the immense generosity of Allah, the Exalted.
It also contains an exhortation for the Muslim to take advantage of these noble acts of worship whenever their means are facilitated.