With two septuagenarian candidates as the front runners for the Democratic presidential nomination, their health — both physically and mentally — has become somewhat of an issue in the campaign.

However, Sen. Bernie Sanders (I-Vt.) said that he would not weaponize questions about former Vice President Joe Biden’s mental health during the campaign.

During a Fox News town hall, Sanders was played a clip of former presidential hopefuls and commentators questioning Biden’s mental health. He said he wasn’t going to ā€œgo at the levelā€ as the two battle it out for the nomination.

ā€œI’m not going to go at that level in attacking him,ā€ Sanders said, ā€œThat’s for people to decide.ā€

ā€œAll I can say is that Joe and I have very significant political differences. I’m not going to be making, you know, personal attacks on Joe. That’s not what I do,ā€ he added.

Watch the video below:

However, Sanders appeared to take a shot at the amount of time that Biden spends answering questions and the length of his rallies — specifically mentioning a recent event when Biden only spoke to supporters for seven minutes.

ā€œLook, I’m here. We’re talking about real issues, and we can go on for three hours talking about them. If I’m going to give a speech to people … I can’t do it in seven minutes. There are too many issues, there’s healthcare, education, climate change, immigration reform, criminal justice reform. I don’t know how you do it in seven minutes. So, all that I’m saying is that I think as a candidate for president, you owe respect to the people.

ā€œAnd you have to have the courage, or the desire, to say, ā€˜Hey, this where I’m coming from this is my view. You disagree with me, fine.’ But I can’t do that in a seven-minute speech,ā€ he added.