I think many people didn't understand this scene here and it's importance.
This scene holds importance because SANJI KNEW THAT ROBIN WAS LYING!
When Robin was telling him and Chopper that she doesn't want to comeback, and it was her wish. Sanji didn't believe her words. He knew she was hiding something and was LYING which in itself is a big deal. Because Robin had framed them and was going to sacrifice herself, however Sanji was unaware of this fact.
For him, the only information was that she had shot Iceberg and framed them for it. STILL HE BELIEVED HER. You need to understand that his belief in her was stronger, even Luffy was unsure and confused but Sanji? He was unfazed and remained firm.
He went on the train after that and then found out why she was doing all that. Till then he didn't have any idea about it all. Going to save someone who had framed you, betrayed you and still believing in them isn't easy. And that's what Sanji did here.
“When a woman lies, it's a man's job to forgive her”, isn't about women or forgiveness, it's about Robin and her lie; that she was willingly leaving the crew. And Sanji's belief in Robin. This scene was shown afterwards but it still holds the same value. Nothing more, nothing less.
It's not about women, lies, forgiveness, or anything of sorts. It's about Sanji's belief in Robin and his understanding of her. He is deeply observant, he notices things people normally overlook and it's mentioned times and times. One example is when they were getting down from sky island and the octopus was shrinking, Sanji was the first to notice it even though it's a very small thing. He also noticed that Law was getting too involved with Doflamingo.
That's all I wanted to say. Look at this scene beyond words. It's not just pretty words, but rather his understanding, observation, belief and kindness. He was ready to forgive her even though he didn't know her situation.
That's all. Thanks for reading my rambling.
