Al-Baqarah 2:186
وَإِذَا سَأَلَكَ عِبَادِى عَنِّى فَإِنِّى قَرِيبٌ ۖ أُجِيبُ دَعْوَةَ ٱلدَّاعِ إِذَا دَعَانِ ۖ فَلْيَسْتَجِيبُوا۟ لِى وَلْيُؤْمِنُوا۟ بِى لَعَلَّهُمْ يَرْشُدُونَ
Wa-itha saalaka AAibadeeAAannee fa-innee qareebun ojeebu daAAwata addaAAiitha daAAani falyastajeeboo lee walyu/minoo beelaAAallahum yarshudoon
"And when My servants ask you, [O Muḥammad], concerning Me - indeed I am near. I respond to the invocation of the supplicant when he calls upon Me. So let them respond to Me [by obedience] and believe in Me that they may be [rightly] guided."
Al-Baqarah 2:186, translation by Sahih International
A short reflection
He answered the question about His nearness with His own nearness, not 'He is close', but 'I am close'.