Abdul-Aziz bin Marwan wrote to Abdullah bin Umar, "Send me word of whatever you need."Abdullah bin Umar wrote back to him, "I heard the Messenger of Allah ﷺ say, 'Begin with those whom you support, and the upper hand is better than the lower hand.' I consider the upper hand to be the one that gives and the lower hand to be the one that asks. I will not ask you for anything, nor will I refuse any provision that Allah drives to me through you."
حدثنا حماد بن مسعدة عن ابن عجلان وصفوان قال أخبرنا ابن عجلان المعنى
أن عبد العزيز بن مروان كتب إلى عبد الله بن عمر أن ارفع إلي حاجتك قال فكتب إليه عبد الله بن عمر إني سمعت رسول الله ﷺ يقول ابدأ بمن تعول واليد العليا خير من اليد السفلى وإني لأحسب اليد العليا المعطية والسفلى السائلة وإني غير سائلك شيئا ولا راد رزقا ساقه الله إلي منك
Both its chains of transmission are sahih. Ahmad related it from two teachers, Hammad bin Masada and Safwan, both of them from Ibn Ajlan. Safwan is Ibn Isa Zuhri Basri Qassam, whose reliability was established earlier at 2075, and we add here that Bukhari gave his biography in al-Kabir 2/2/310, saying he heard from Ibn Ajlan and Bishr bin Rafi. Ibn Ajlan is Muhammad bin Ajlan. The hadith is given at length at 4474, see also 6039.