{تَصُدُّونَ} {avert}: You prevent, you make a barrier between people and faith.
{تَبْغُونَهَا عِوَجًا} {seeking to make it [seem] deviant}: You want it to be deviant, not on the creed of your father Ibrahim (pbuh). The word “deviant” here comes in contrast to Hanifa (true MUslim).
So Ibrahim (pbuh), wanted it to be a straightforward (hanifa), while the Jews denied everything that the Prophet (saws) has come with, they wanted it crooked.
وَأَنتُمْ شُهَدَاء {while you are witnesses}: They are witnesses with their Torah, and what is meant is the part of it that remained undistorted, Allah (swt) told them:
فَأْتُواْ بِالتَّوْرَاةِ فَاتْلُوهَا
{“So bring the Torah and recite it, if you should be truthful.”} (Ali-Imran: 93)
The Torah contains things that are not distorted, but they refused to bring the Torah; Because they are liars.
وَمَا اللّهُ بِغَافِلٍ عَمَّا تَعْمَلُونَ {And Allah is not unaware of what you do.}:
Whatever you do in secret or openly, Allah (swt) is aware of it and is not unaware of you. He (swt) counts all your words and deeds, for everything that the Jews have distorted, changed and altered from the Torah, is not hidden from Allah (swt), and He will recompense them for it.