Khidmat, To call out brothers for khidmat, Putting yourself forward for khidmat

We set out on an expedition along with The Messenger of Allah “Allah’s blessings and peace be upon him” until it was evening, and we had been near a water reservoir of Arabia. The Messenger of Allah “Allah’s blessings and peace be upon him” said “ Who would be the person who would go ahead and set right the reservoir and drink water himself and serve us with it?” Jabir said “I stood up and said: The Messenger of Allah, it is I who am ready to do that.” Thereupon Messenger of Allah “Allah’s blessings and peace be upon him” said “Who is the person to accompany Jabir?” and then Jabar Ibn Sakhr stood up. So we went to the well and poured in that tank a bucket or two of water and plastered it all with clay and then began to fill it (with water) until it was filled to the brim. Messenger of Allah “Allah’s blessings and peace be upon him” was the first who appeared before us, and he said “Do you (both) permit me to drink water out of it?” We said “Yea, The Messenger of Allah”. He led his camel to drink water and it drank. He then pulled its rein and stretched his legs and began to urinate. He then took it aside and made it kneel down at another place and then came to the tank and performed ablution. I then got up and performed ablution like the ablution of The Messenger of Allah “Allah’s blessings and peace be upon him”, and Jabbar Ibn Sakhr went in order to relieve himself and The Messenger of Allah “Allah’s blessings and peace be upon him” got up to observe prayer and there was a mantle over me. I tried to invert its ends but it was too short (to cover my body easily). It had its borders. I then inverted it (the mantle) and drew its opposite ends and then tied them at my neck. I then came and stood upon the left side of The Messenger of Allah “Allah’s blessings and peace be upon him”. He caught hold of me and made me go round behind him, until he made me stand on his right side. Then Jabbar Ibn Sakhr came. He performed ablution and then came and stood on the left side of The Messenger of Allah “Allah’s blessings and peace be upon him”. Then The Messenger of Allah “Allah’s blessings and peace be upon him” caught hold of our hands together, pushed us back and made us stand behind him. Then The Messenger of Allah “Allah’s blessings and peace be upon him” began to look upon me with darting looks, but I did not perceive that. After that I became aware of it and he pointed with the gesture of his hand that I should wrap my loin cloth. When The Messenger of Allah “Allah’s blessings and peace be upon him” had finished the prayer, he said “Jabir!” I said “The Messenger of Allah at thy beck and call” He said “When the cloth around you is inadequate, then tie the opposite ends but when it is small, tie it over the lover body.”
(Sahih Al- Muslim)
Note:
• In the Markaz we often hear the announcement being made “who is ready for khidmat?” and when a brother stands a second announcement is made “who is ready to accompany etc…”
• Also when out in jamaat mostly 2 brothers are chosen for kidhmah, which also conforms to this hadith.