Texts supporting taquiya:
It is permissible to speak words of unbelief when al-Taqiyya is
mandatory."
“al-Taqiyya is the uttering of the tongue, while the heart is
comfortable with faith.”
“al-Taqiyya is with the tongue only; he who has been COERCED into
saying that which angers Allah (SWT), and his heart is comfortable
(i.e., his TRUE faith has NOT been shaken.), then (saying that which
he has been coerced to say) will NOT harm him (at all); (because) al-
Taqiyya is with the tongue only, (NOT the heart).”
The nonbelievers arrested Ammar Ibn Yasir (RA) and (tortured him until) he (RA) uttered foul words about the Prophet (PBUH&HF), and praised their gods (idols); and when they released him (RA), he (RA) went straight to the Prophet (PBUH&HF). The Prophet (PBUH&HF) said: "Is there something on your mind?" Ammar Ibn Yasir (RA) said: “Bad
(news)! They would not release me until I defamed you (PBUH&HF) and
praised their gods!” The Prophet (PBUH&HF) said: “How do you find
your heart to be?” `Ammar (RA) answered: “Comfortable with faith.” So
the Prophet (PBUH&HF) said: “Then if they come back for you, then do
the same thing all over again.” Allah (SWT) at that moment revealed
the verse: “…except under compulsion, his heart remaining firm in
faith…[16:106]”
“The meaning that Allah (SWT) is conveying is that he who utters
unbelief after having believed, shall deserve the Wrath of Allah (SWT)
and a terrible punishment. However, those who have been coerced, and
as such uttered with their tongues that which their hearts did not
confirm to escape persecution, have nothing to fear; for Allah (SWT)
holds His (SWT) servants responsible for that which their hearts have
ratified.”
Ibn Abi Shaybah, Ibn Jarir, Ibn Munzir, and Ibn Abi Hatim narrated
on the authority of Mujtahid (a man’s name) that this verse was
revealed in relation to the following event: A group of people from
Mecca accepted Islam and professed their belief; as a result, the
companions in Medina wrote to them requesting that they emigrate
to Medina; for if they don’t do so, they shall not be considered
as those who are among the believers. In compliance, the group left
Mecca, but were soon ambushed by the nonbelievers (Quraish) before
reaching their destination; they were coerced into disbelief, and they
professed it. As a result, the verse “…except under compulsion, his
heart remaining firm in faith [16:106]…” was revealed."
The Prophet (PBUH&HF) saw Ammar Ibn Yasir (RA) crying, so he (PBUH&HF) wiped off his (RA) tears, and said: "The nonbelievers arrested you and immersed you in water until you said such and such (i.e., bad-mouthing the Prophet (PBUH&HF) and praising the pagan gods to escape persecution); if they come back, then say it again." After the conquest of the city of Khaybar by the Muslims, the Prophet (PBUH&HF) was approached by Hajaj Ibn Aalat and told: “O Prophet of
Allah: I have in Mecca some excess wealth and some relatives, and I
would like to have them back; am I excused if I bad-mouth you (to
escape persecution)?” The Prophet (PBUH&HF) excused him and said:
“Say whatever you have to say.”
And there are more, all of this are sunnis sources.