How we cite our quotes:
It was […] as if an unbreakable pact were being sealed. He started at the dragon and a cold tingle ran down his arm. (5.40)
Eragon and Saphira's friendship isn't just something casual; it's described as an "unbreakable pact." That's not something to mess with. We bet they've got themselves a pair of these.
Tomorrow you will ride me […] or else I will carry you in my claws. Are you a Dragon Rider or not? Don't you care for me? (21.59)
Like every friendship, Eragon and Saphira's relationship has its ups and downs. Eragon is afraid to ride Saphira, but Saphira takes his aversion personally. Her sensitivity, though, just shows how much she values his friendship. She wants them to ride together, as a team, so that she can keep him safe.
[Saphira:] If anything happens, I'm going to pin you to my back and never let you off.
[Eragon:] I love you too.
[Saphira:] Then I will bind you all the tighter. (24.7-9)
Here's another glimpse of Saphira's protective concern for Eragon. She's always having to be sent off to the woods to hide while Eragon goes into the town to deal with some danger or other. Like a true friend, she worries for the poor guy's safety. For his part, Eragon seems to recognize her concern as a sign of love. He's intuitive like that.