। ॥ २८७ ॥
In plain words
Give no opening at all — not to sleep, not to idle talk about the world, not to sounds or any pull of the senses, not even to forgetting — and, within yourself, contemplate the Self.
Close to the Sanskrit
Giving no opportunity, anywhere, to sleep, to worldly talk, to sound and other [sense-objects], or even to forgetfulness [of the Self], contemplate the Self in the self.