Sri Guru Granth Sahib Ji Arth Ang 52 post 11

ਗੁਰੁ ਸਮਰਥੁ ਅਪਾਰੁ ਗੁਰੁ ਵਡਭਾਗੀ ਦਰਸਨੁ ਹੋਇ ॥
Gur Samarathh Apaar Gur Vaddabhaagee Dharasan Hoe ||
गुरु समरथु अपारु गुरु वडभागी दरसनु होइ ॥
The Guru is All-powerful, the Guru is Infinite. By great good fortune, the Blessed Vision of His Darshan is obtained.

ਗੁਰੁ ਅਗੋਚਰੁ ਨਿਰਮਲਾ ਗੁਰ ਜੇਵਡੁ ਅਵਰੁ ਨ ਕੋਇ ॥
Gur Agochar Niramalaa Gur Jaevadd Avar N Koe ||
गुरु अगोचरु निरमला गुर जेवडु अवरु न कोइ ॥
The Guru is Imperceptible, Immaculate and Pure. There is no other as great as the Guru.
ਸਿਰੀਰਾਗੁ (ਮਃ ੫) (੯੯) ੨:੨ – ਗੁਰੂ ਗ੍ਰੰਥ ਸਾਹਿਬ : ਅੰਗ ੫੨ ਪੰ. ੧੩
Sri Raag Guru Arjan Dev