法華文句記 7.67

7.67

身若同類誘之必來，汝身猶勝必令彼懼，故告使言不須彊以勝身化之，故云「勿彊」。

If the body is of the same kind, enticing him will surely make him come; if your body is still superior, it will certainly cause him fear. Therefore he told the messenger that he did not need to forcibly convert him with a superior body; hence it says "do not force."