觀無量壽佛經疏 3.105

3.105

四、從是故應當下，至三佛陀已來，正明如前所益專住必成，展轉相教勸觀彼佛也。

Fourth, from "Therefore you should" down to "saṃbuddha" directly clarifies that through the aforementioned benefit, dedicated stabilization is sure to succeed, and one should progressively instruct and encourage others to contemplate that Buddha.