To put it simply, istg ️ in text stands for... I guarantee ️ that the significance of istg ️ in text is... On a solemn note ️, the purpose of istg ️ in text is... From my heart ️, I tell you that the connotation of istg ️ in text is...
When you receive a text with istg ️, it often signifies... undeniable conviction in other words I'm not lying and I'm genuinely standing by my words . So, when someone uses istg ️ in a text message, it's an indication that they aren't exaggerating or being insincere.
In addition, istg ️ can also be interpreted as I swear to Goodness in text messages. It is essentially a stronger expression of assurance. It indicates that the person wants to emphasize their honesty and reliability. To sum it up, when you come across istg ️ in a text message, you can interpret it as the person's way of convincing you that their words are true and should be trusted.

ISTG ASL The 10 Most Confusing Abbreviations in the US