[eladiopsislab]

"not to grasp and the signs and features of forms, odours, sounds etc and to hold the senses restrained"

I think "Not to grasp" means not to take them as self or belonging to self. Take them for what they are. Just form, just sound etc. Do not identify with them as self or things belong to self. It is the practice

Friends, these six are the conscious bodies:

eye-consciousness,
ear-consciousness,
nose-consciousness,
tongue-conscioussness,
body-consciousness and
mind-consciousness.

With the arising of determinations arise consciousness, with the cessation of determinations consciousness ceases. This same noble eightfold path is the path to the cessation of consciousness, namely, right view, right thoughts, right speech, right actions right livelihood, right effort, right mindfulness, and right concentration. When the noble disciple knows consciousness thus, the arising of consciousness thus, the cessation of consciousness thus and the path to the cessation of consciousness thus, he gives up the latent tendencies to greed, drives out the latent tendencies to aversion, and, completely destroying the latent tendency to measure as `I be', dispels ignorance, arouses science, and here and now makes an end of unpleasantness.

MN 9