Shiva Purana
सर्वावस्थां गतस्यापि मयि भक्तिमतः परम् ॥ सिध्यत्येव न संदेहो नापरस्य तु कस्यचित् ॥ ६६ ॥
There is no doubt in this that this mantra becomes efficacious in the case of a man endowed with devotion to me whatever be his condition. It is not so in the case of other mantras.
english translation
sarvAvasthAM gatasyApi mayi bhaktimataH param ॥ sidhyatyeva na saMdeho nAparasya tu kasyacit ॥ 66 ॥
hk transliteration by Sanscript