Shaykh Salih al-Ja’fari says:
“Know if you recite, la ilaha illa Allah, alone you will be in the realm of negation and affirmation. The word, ‘la’, negates from your nafs anything of its darkness and when you affirm ‘illa Allah’ the lights from the greatest name of Allah descend upon you, and that light prepares you for the Muhammadan ‘with-ness’.
And when you say, ‘Muhammad is the Messenger of Allah’ ﷺ and you witness him with your heart, you will be with him ﷺ, in a with-ness of the vision with the heart and soul connection which by it your soul will long to witness your Lord. And you will enter His saying, Exalted is He, “Muhammad is the Messenger of Allah, and those with him”. Since he ﷺ is the door of Allah, the Exalted, and it is not possible to enter His presence except by him ﷺ.”