Al-Mu'jam al-Awsat 3292 — to Sayyiduna Umar bin al-Khattab: Tell us

Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) relates that it was said to Sayyiduna Umar bin al-Khattab (may Allah be pleased with him): "Tell us about the hour of hardship (sa'at al-'usrah)." Sayyiduna Umar (may Allah be pleased with him) said: "We set out with the Messenger of Allah (peace and blessings be upon him) towards Tabuk in intense heat. We halted at a stopping place where we were struck by such thirst that we thought our necks would be severed, so much so that a man would go to search for water and come back thinking that his neck would be severed, and so much so that a man would slaughter his camel, squeeze out the contents of its stomach and drink it, and rub what was left on his liver. Then Sayyiduna Abu Bakr (may Allah be pleased with him) said: 'O Messenger of Allah, Allah Almighty has accustomed you to good in supplication (that is, He answers your supplication), so supplicate for us.' He (peace and blessings be upon him) said: 'Do you want that?' He said: 'Yes.' Then he (peace and blessings be upon him) raised his hands, and he had not yet lowered them when the clouds gathered and it began to rain; then when the rain stopped, the people filled the vessels they had with them."
Imam al-Tabarani (may Allah have mercy on him) said: "No one narrated this hadith from Nafi' bin Jubayr except Utbah, and Sa'id bin Abi Hilal is alone in narrating it."