Shiva Purana
अत एव हि कालाग्निरधस्ताच्छक्तिरूर्ध्वतः ॥ यावदादहनं चोर्ध्वमधश्चाप्लावनं भवेत् ॥ १० ॥
That is why the Kālāgni stays below and the Śakti upwards. The upward blazing is till burning and the downward flow is till complete drenching.
english translation
ata eva hi kAlAgniradhastAcchaktirUrdhvataH ॥ yAvadAdahanaM cordhvamadhazcAplAvanaM bhavet ॥ 10 ॥
hk transliteration by Sanscript