大毘盧遮那成佛經疏 2.37

2.37

第七「云何決定心？謂遵教命如說奉行。第八云何疑心？謂常收持不定等事」者，今先釋疑心，令決定心相易解明了故。謂此人隨有所聞，便生不決定心。如受戒時，便自生疑心：「我今定得戒，為不得戒耶？」或疑師疑法，諸事例爾。如人道行，以疑惑故不能前進。《智度》偈云「乃至譬如觀岐路，好利者應逐。」是彼對治。又決定心者，謂隨聞善友等如法教命，便即不生疑慮，至心奉行。然亦當以慧觀察，生正決定心也。

Seventh: regarding "What is the resolute mind? It means honouring instructions and orders and practising as taught. Eighth: What is the mind of doubt? It means constantly holding onto indeterminate matters": here the mind of doubt is explained first, so that the mark of the resolute mind will be easily understood and clear. This means that whatever this person hears, an irresolute mind immediately arises. For example, when receiving the precepts, the doubt immediately arises within oneself: "Do I now definitely obtain the precepts, or do I not obtain the precepts?" Or one doubts the master or doubts the Dharma; all instances are like this. It is like a person travelling on a road who, because of doubt and hesitation, is unable to advance. A verse in the Mahāprajñāpāramitopadeśa says: "[…] just like looking at a fork in the road: one should follow the beneficial path." This is its antidote. Furthermore, regarding the resolute mind: this means that as soon as one hears the instructions and orders of good friends and the like that accord with the Dharma, no doubt or hesitation arises, and one practices them with all one's heart. Yet one should also examine with wisdom to give rise to the correct resolute mind.