Anguttara Nikaya 1:37
SUJATO‘Na kho ahaññeveko byādhidhammo byādhiṁ anatīto, atha kho yāvatā sattānaṁ āgati gati cuti upapatti sabbe sattā byādhidhammā byādhiṁ anatītā’ti.
‘It’s not just me who is liable to get sick, not being exempt from sickness. For all sentient beings get sick according to their nature, as long as they come and go, pass away and are reborn.’