As you may know, Shiv Purana says Vishnu Bhagavan and Laxmi Mata are only externally Saatvik looking but their true nature is Taamsik (Here). Skand Puran also says Vaishnav Puranas are Taamsik and shouldn't be read by Brahmins (Here).
Here's one more:
Soot Gita (2.40-41): asti rudrasya viprendrA antaH sattvaM bahistamaH | viShNorantastamaH sattvaM bahirasti rajoguNaH || antarbahishcha viprendrA asti tasya prajApateH (Original with Sanskrit explanation)
This definitely seems to say that Vishnu has a tamasic body. As per Smriti sect/Shankaracharya following website, there is another confirmation in Shiva Dharmottara Purana.
Shiv Dharmottar Puran (unknown): antah sattvagunopeto bahistaamasasamyutah shuddha saattvika ityuktah shankaro lokashankarah antastaamasa shamyuktto bahih sattvagunaanvitah shuddha taamasa ityukto vishnussaakshaat sriyah patih
Can somebody please fully translate both these sentences and also find exact references/links for the second one?