El burro hablando de orejas
This saying is used to talk about an inappropriate leader who would eventually lead their followers to a disgraceful situation.
This idiom was first used in the Bible, in Matthew 15:14 we can find, “And if the blind lead the blind, both shall fall into a ditch”. We currently use it when we notice a person trying to teach others how to do things at which they have always been unsuccessful.
No hay mal que por bien no venga
This idiom refers to something that looked bad at the very beginning, but in the very end, it became a fortunate happenstance in our lives.
During the XIX, a poet first used this expression in one of his works. This poet narrated the hardships a person had to go through. However, in the very end, these misfortunes turned into advantages to the supposedly unlucky character. Nowadays, we use this saying to mean that an initial misadventure brought about happy consequences to us.