姚约,湖州仙潭人。潜心内典,觉海友公兴净业社,约实主其事。忽告友公曰,久厌浮生,不日西去,师可助我念佛。友遂日与诵佛名。一日,就座而化。既而见梦于友曰,约已往生净土,师之力也。友曰,欲从公游,得乎。约曰,师世寿未尽,寺中景懿当先至。懿,同社僧也,阅月便终。(佛祖统纪)