MN64 tends to support what @kensho posted, provided that one understands doubt to be something which obscures Nibbana:
The Buddha said this:
"Ānanda, take an uneducated ordinary person who has not seen the noble ones, and is neither skilled nor trained in the teaching of the noble ones. They’ve not seen good persons, and are neither skilled nor trained in the teaching of the good persons.
Their heart is overcome and mired in identity view,
and they don’t truly understand the escape from identity view that has arisen.
That identity view is reinforced in them, not eliminated: it is a lower fetter.
Their heart is overcome and mired in doubt,
And MN121 is similarly suggestive in its post-enlightenment practice:
Whatever ascetics and brahmins enter and remain in the pure, ultimate, supreme emptiness—whether in the past, future, or present—all of them enter and remain in this same pure, ultimate, supreme emptiness.
So, Ānanda, you should train like this: ‘We will enter and remain in the pure, ultimate, supreme emptiness.’