佛說觀佛三昧海經 4.26

4.26

佛告阿難：「佛滅度後佛諸弟子，見佛胸相光者，除却十二万億劫生死之罪，若不能見胸相分明者入塔觀之。如是觀者名為正觀，若異觀者名為邪觀。

The Buddha told Ānanda: "After the Buddha’s parinirvāṇa, if the Buddha’s disciples see the light of the mark on the Buddha's chest, they will eliminate the sins of birth and death of twelve myriad koṭis of kalpas. If they cannot see the mark on his chest clearly, they should enter a stūpa to contemplate it. Such contemplation is called correct contemplation; if one contemplates otherwise, it is called false contemplation."