Life and Vow
The sources record that Joseph suffered from various diseases over a long period, which is the origin of his epithet 'the Much-Ailing.' In the midst of his grievous illness he prayed to God and made a vow that, should the Lord grant him health, he would serve the brethren of the Kiev Caves Monastery until the end of his days.
Having recovered from his ailments, he entered the monastery, was tonsured a monk, and devoted himself to fasting and prayer. The tradition relates that he kept his vow faithfully, serving the brotherhood in obedience until his death.