Wéijǐn 惟謹 (mid- to late-Tang, dates unknown) — Tang Esoteric monk of the Jìngyǐng-sì 淨影寺 Bǐqǐ-yuàn 比綺院 in Cháng-ān, designated as a wǔbù chí-niàn sēng 五部持念僧 — a “monk practising the recitation of the Five Sections” of the Esoteric abhiṣeka (Buddha, Vajra, Lotus, Karma, and Jewel families). His best-known surviving work is the brief but doctrinally substantial Dà Pílúzhēnà jīng ācāryā zhēnshízhì-pǐn zhōng ācāryā zhù a-zì guānmén 大毘盧遮那經阿闍梨真實智品中阿闍梨住阿字觀門 (KR6j0021, T18n0863) — an exposition of the a-ji-kan 阿字觀 (contemplation on the seed-syllable A) drawn from the Mahāvairocana-sūtra.
Lifedates and native place are not preserved. The Jìngyǐng-sì 淨影寺 was the principal Cháng-ān monastery established by Huìyuǎn 慧遠 of the Sui period and continued to be a major teaching centre under the Tang. Wéijǐn’s affiliation with the Bǐqǐ-yuàn sub-cloister and his designation as a wǔbù chí-niàn sēng place him in the second-generation Esoteric establishment, after the principal Tang masters (Śubhakarasiṃha, Vajrabodhi, Amoghavajra) but in a transmitted lineage from them.
His sole extant work is the short a-ji-kan exposition (KR6j0021); no further biographical material is preserved.
Source: KR6j0021 colophon (T18n0863); standard Esoteric biographical compendia note his obscurity.